None of the countries would elaborate on the intelligence that prompted the advisory, but Britain's Foreign Office said it was 'aware of a specific and imminent threat.'

The eastern city of Benghazi, Libya, was an opposition stronghold in the… (Luis Sinco / Los Angeles…)

LONDON — Britain, Germany and the Netherlands urged their citizens Thursday to leave the eastern Libyan city of Benghazi immediately, citing an imminent threat to Westerners months after an assault on the U.S. mission there killed four Americans.

None of the countries would elaborate on the intelligence that prompted the advisory, but Britain's Foreign Office said it was "aware of a specific and imminent threat."

The stark warning came a day after Secretary of State Hillary Rodham Clinton testified before Congress about the Sept. 11 attack in Benghazi that killed U.S. Ambassador J. Christopher Stevens and three other Americans. Concern over terrorist activity in the region has risen in light of French intervention in Mali to counter Islamic militants and the just-concluded hostage crisis in Algeria, in which more than 30 foreigners were abducted and slain by Muslim radicals.

Italy last week suspended activity at its Benghazi mission and pulled out diplomatic staff after a gun attack on its consul, who was traveling in a heavily armored car and was not injured.

The incident illustrated the security challenges facing Benghazi more than a year after the fall of Libyan dictator Moammar Kadafi. Britain began warning its nationals to steer clear of all but a few Libyan cities since the September attack, with Benghazi on its list of places to avoid.

The Dutch Foreign Ministry had also issued a bulletin Monday noting the danger of traveling to Benghazi and its environs, spokesman Thijs van Son said. On Thursday, the ministry advised all Dutch nationals to vacate the city.

"We see upcoming threats so … we added this advice of not staying there," Van Son said. About 10 Dutch citizens were known to be in the Benghazi area.

Germany issued a similar alert Thursday.

The U.S. State Department reiterated its advice to avoid travel to Benghazi but did not cite any new intelligence.

"Although there is no specific information pointing to specific, imminent threats against U.S. citizens, the potential for violence and kidnappings targeting Westerners in Benghazi is significant," the department said.

After the British announcement, a Libyan official expressed surprise at the ramped-up security warning.

"We acknowledge that there are security problems in Benghazi and that there have been for several months, but there is no new intelligence that could justify this reaction from London," Deputy Interior Minister Abdullah Massoud told Agence France-Presse.